There are few theological and philosophical ideas current in his day on which Gregory does not touch, but he wrote no coordinated studies of the sort Augustine attempted in his books on the Trinity or Christian Learning or Freedom of Choice. His views are to be found piecemeal in various contexts, where he discusses problems as they arise. He does so chiefly in the course of exegesis, but also, as we have seen, in the Dialogues, where there is reflection on the soul, on the nature of death, on resurrection, on the character of the life to come, as Gregory and Peter the Deacon consider what is to be learned by observing the deaths of holy men. The Regula Pastoralis, Gregory's only work with a single theme, deals, not strictly with a topic of speculative theology (as Boethius would have recognised the notion), but with the practical and theoretical aspects of the work and responsibilities of a bishop.

Fragmentary though it is, however, there is a very great deal of theology diffused through Gregory's writings, and taken as a whole it forms a complete system. Gregory is a theologian without deep intellectual anxieties. His own active struggle was with the difficulty of maintaining a balance between the demands of this world and his longing for the next, and he wrote accordingly on the spiritual life and on pastoral care. Augustine woke in the night sometimes because an unsolved philosophical or theological problem was troubling him.